The heart and soul of the world’s solar industry is gathered this week in Long Beach for the annual SEPA/SEIA solar conference. Five years ago, this conference drew 200 people to a dingy hotel ballroom in Reno. This year, it’s sold out the Long Beach Convention Center, and you can’t get a hotel room for love or money within a 20-mile radius. It’s like the Super Bowl is in town.

Solar has come a long way — and there’s a lot of things to thank for what’s brought the industry to this point. Certainly, the world owes the German feed-in tariff a big danke for all it has done to scale up manufacturing. And in the U.S., the California Solar Initiative has been the big driver, with a bevy of new state programs vying for the crown. While everyone is encouraged by the progress First Solar has made delivering on thin-film’s long-deferred promise, I’d argue that to date, financial innovation — more specifically solar PPAs — has been a bigger driver in expanding markets than technological innovation.

So, the question of the day is: what’s the new development that will emerge as the biggest theme of this year’s conference? At the risk of blogmiscuity, I’m guest-blogging on just that question over at RenewableEnergyAccess. Check it out.

Grist thanks its sponsors. Become one.